[python] Re: Geared Steering
- From: Kelvin Arthur <kelvin.arthur@xxxxxxxxx>
- To: "python@xxxxxxxxxxxxx" <python@xxxxxxxxxxxxx>
- Date: Wed, 29 May 2013 06:28:16 +1200
Hi all
The first version of my python I got up to 65km/h, it was pretty scary, but I
flew past a road bike going down the same hill, and I ran out of gearing at
35km/h! I think experience will make the difference. Thinking back, if I had
had handlebars, there's no way I would have been touching them, I was
concentrating much too hard on what I was doing.
I tried putting handlebars on it when I was first learning to ride, but quickly
realised that they weren't actually helping me, so they came off and I pushed
on.
The idea may well have merit, but I think one of the posts had a good point,
handlebars are naturally counter-intuitive on a python...
My 5 cents worth...
Sent from my iPad
On 29/05/2013, at 5:25, Patrick van Gompel <patrick_van_gompel@xxxxxxxxxxx>
wrote:
> Ah ok. Well sorry, I have no experience with driving 66+km/h on a Python.
> Even on a recumbent (Condor) I get a little scary when driving 70km/h and
> whould never take my Python that far.
> So I am sorry I can't help you much with those speeds and I can't tell what
> the effect of a normal handle bar would be.
> You were talking about a 'low-walker', so that confused me, because I don't
> think that a Python is slow. I have never been able to pedal my Python faster
> than I could handle, but hey, I am no speed machine ;-) And there aren't
> hills around here to get 66+km/h speeds.
> Patrick
>
> Date: Tue, 28 May 2013 12:17:57 -0400
> Subject: [python] Re: Geared Steering
> From: weyounet@xxxxxxxxx
> To: python@xxxxxxxxxxxxx
>
> well I was thinking mostly to stabilize things like going downhill very fast,
> I read a review online that said it was "puckerish" and he could only achieve
> a speed of 66kph vs 90+kph with rigid boom, had to engage the break and even
> then it wasn't pleasant.
> http://www.recumbents.com/forums/topic.asp?TOPIC_ID=4226
>
> I like the python center-steering, but I'd also like to be able to go fast
> downhill without having to do too much work getting it to go straight. There
> are a bunch of hills in my area with relatively high speed traffic, so it's
> important that can maintain control.
>
> If ordinary handlebars are enough to make it easy to go downhill at high
> speed, then I guess that'll be enough,
> it was just my understanding from that post that it wasn't, though perhaps
> they weren't using handlebars for that downhill testing.
>
>
> On Tue, May 28, 2013 at 11:13 AM, Patrick van Gompel
> <patrick_van_gompel@xxxxxxxxxxx> wrote:
> My thoughts:
> A Python is a leg/hip steered bike. You can have handle bars anyway you like,
> but for a newcomer it might be even more confusing. You really need to learn
> to steer in a different way and forget about steering with your hands.
> I did have and still have a handle bar on my Python(trike). When I learnt to
> cycle I always got rather tired arms, because my legs would go one way and my
> arms tried to correct that (which was bad). Now I use the handle bars for
> extra stability and sharp cornering.
> Looking at your drawing:
> Unless you succeed in making this a durable construction I doubt it will
> survive the big forces for much time.
> I am not saying you should't try it, but why do you prefer this construction
> above a simple handle bar?
> Why are you worried for the forces at high speeds? I am more worried for slow
> speeds and when you legs go one way and your arms try to go the other way. At
> high speeds you don't need much force to steer imo.
> I am not entirely sure, but if you have a 1:1 ratio I think you will have a
> hard time steering your bike with your arms only. Though, it also depends on
> the lenght of your levers.
>
> Patrick
>
> Date: Tue, 28 May 2013 10:44:57 -0400
> Subject: [python] Re: Geared Steering
> From: weyounet@xxxxxxxxx
> To: python@xxxxxxxxxxxxx
>
>
> hmm, well the ones I linked to are 3:1 and I think it's already too much, I
> think 1:1 is okay considering have levers at both arms, and it also would
> make it the same refinement of motion as on a normal bike.
>
> Based on your recommendation, you might have a different Idea than I about
> how the gears are to be implemented, so I've drawn a crude crayon diagram to
> hopefully get us ":on the same page"
>
> I made it based on the picture of the pivot at
> http://www.python-lowracer.de/pics/kick_stand_with_steering_stop.jpg the
> gear would go approximately where the bell is now.
>
> Also I realize having the diagonal levers may make it too close to the seat,
> so could probaly make them kinda like L's so they give enough clearance.
>
>
> On Tue, May 28, 2013 at 9:34 AM, Peter Švančárek <peter.svancarek@xxxxxxxx>
> wrote:
> to low gearing ratio probably... long lever would be better.
> Maybe planetary gear would be better? with ratio at least 1:10-20
>
> Dňa 28. 5. 2013 15:15 Logan Streondj wrote / napísal(a):
> Hey,
> I was wondering if can improve the steering at high speeds,
> perhaps by having some kind of gearing mechanism on the pivot,
> that would for instance move levers on either side,
> the levers could be used to hold the pivot at a certain angle, or change it
> to an appropriate one.
>
> perhaps bevel gears could be used.
> If for instance the lever gears are mounted on the back boom,
> and the pivot gear controls the front boom,
> then could have very precise control of the front-back boom angle.
> main issue I guess would be finding good mounting options,
> and making sure it has enough strength to withstand the forces at high
> speeds.
>
>
> That way can finally achieve the inital goal of using it as a low-racer,
> rather than a low-walker as it kinda is now.
> who knows, might even win at some recumbent bicycle races.
>
> It may also make it easier to learn for newcomers, since there would be some
> kind of steering available.
>
> Perhaps something like the larger of these gears could be used
> http://www.ebay.ca/itm/5-9mm-Pinion-Shaft-Dia-Straight-Bevel-Gear-Spare-Parts-/390574215222?pt=LH_DefaultDomain_0&hash=item5af0099036
> they are $10 on ebay and I saw some for 6 not too long ago, would need
> three, one for the pivot, and two for the levers on either side.
>
>
>
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